Adding headers

To add a custom header to the http requests sent out by the GraphQL Client, annotate your method or the API interface as @Header, e.g.:

@GraphQLClientApi
interface SuperHeroesApi {
    @Header(name = "S.H.I.E.L.D.-Clearance", constant = "TOP-SECRET")
    List<SuperHero> allHeroesIn(String location);
}

The name has to be fixed, but the value can be specified with a constant or the name of a method for dynamic values, e.g.:

@GraphQLClientApi
interface SuperHeroesApi {
    @Header(name = "S.H.I.E.L.D.-Clearance", method = "establishShieldClearance")
    List<SuperHero> allHeroesIn(String location);

    static Clearance establishShieldClearance() { 
        return userIsInRole(MANAGER) ? TOP_SECRET : PUBLIC;
    }
}

• This value is an enum, but it can be any Object; the GraphQL client calls toString() to convert it.

The method must be static and accessible by the interface, i.e. in the interface itself or in one of the classes it’s nested in; if it’s in a different class, prefix it with the fully qualified class name and a dot ".", e.g. @Header(name = "S.H.I.E.L.D.-Clearance", method = "org.superheroes.SecurityTools.establishShieldClearance").

A third option is to pass the value of a header as an API method parameter:

@GraphQLClientApi
interface SuperHeroesApi {
    List<SuperHero> allHeroesIn(String location, @Header(name = "S.H.I.E.L.D.-Clearance") Clearance clearance);
}

The @Header parameter will not part of the GraphQL query.

@Header annotations can also be defined via @Stereotype.

Authorization headers

To add an Authorization header, instead of using the generic @Header annotation, you can also use the special @AuthorizationHeader annotation. It produces a BASIC Authorization header by default or a BEARER token. You can configure the credentials in MP Config with a prefix plus /mp-graphql/ and either username and password for BASIC or bearer for BEARER. The config key defaults to the fully qualified name of the GraphQLClientApi interface or its configKey.

You can use a custom prefix by setting the confPrefix. The infix /mp-graphql/ is still applied, unless you end the confPrefix with *, e.g. @AuthorizationHeader(confPrefix = "org.superheroes.security.basic.* will use org.superheroes.security.basic.username, while * will use plain username.

@AuthorizationHeader annotations can be defined via @Stereotype.